On Monday 03 April 2006 08:09, David Menendez wrote: > If you look at it in terms of folds over pairs, > > cata (&) (x,y) = x & y -- corresponds to uncurry > ana f g x = (f x, g x) -- corresponds to (&&&) > > Then you can de-forest: > > hylo (&) f g x = f x & g x > > -- hylo (&) f g == cata (&) . ana f g > -- == uncurry (&) . f &&& g > -- > -- cata (&) == hylo (&) fst snd > -- ana f g == hylo (,) f g > > This seems remeniscent of pull-backs (or push-outs) in category theory, > but I don't know enough to say for certain.
I especially like the above code after it has been automatically transformed to use the puppy operator by my email client. Actually, the more I look at it... maybe the new crop of haskell editors should define some 'haskicon' replacements. :) Daniel
<<attachment: puppy_op.jpg>>
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